Russia said its forces had taken back several villages last week.
The outcome of the fighting in Kursk could have a significant impact on the course of the war that began with Russia’s full-scale invasion of Ukraine in February 2022.
If it can hold on to a slice of Russian territory, Ukraine will have a valuable bargaining chip in any future peace negotiations.
On the other hand, its decision to commit a substantial force to the Kursk offensive has come with a price elsewhere on the battlefield, as Russia advanced in eastern Ukraine at its fastest pace for two years in August and September.